1. Field of the Invention
This invention relates to a filter of a photoelectric touch panel of the type wherein a light emitting element array and a light receiving element array are assembled into the form of a frame around a faceplate so as to generate infrared beams in the form of a matrix and its coordinate is input into a computer through detection of the position of of a finger or touch pen, which is interposed in front of the optical elements.
2. Description of the Prior Art
In the field of photoelectric touch panels, generally, an accurate matrix is formed by narrowing each infrared beam, and there has been known the technique of disposing a lens on the front of each optical element.
However, this technique of disposing lenses increased correspondingly the number of parts and the work of disposing the lenses in correspondence with the individual optical elements was troublesome. Photoelectric touch panels are also provided with a filter in the form of a frame in front of the optical elements around the faceplate of the display in order to prevent light external to the panel from affecting the light receiving elements and, conversely, to prevent light from the light emitting elements from being projected outside the panel.